Screening for texturing Leuconostoc and genomics behind polysaccharide production

Synthesis of polysaccharides by Leuconostoc can result in improved texture of fermented products. A total of 249 Leuconostoc strains were screened for homo-polysaccharide production and for texturing capabilities in milk. A total of six Ln. mesenteroides strains with superior texturing properties had the genetic blueprint for both homo- (HoPS) and hetero-polysaccharide (HePS) synthesis. Only one strain produced texture in milk without added sucrose, suggesting HePS synthesis via the Wzy dependent pathway. In milk acidification experiments with added sucrose, all six strains depleted the sucrose and released fructose. Thus, they can be used for both texture and possibly also for sweetness enhancement.